利用風力發電機轉子系統作為系統穩定方式之研究

風能是一個乾淨的、環保的再生能源，雖然是取之不盡、用之不竭，但目前仍然有許多缺點使風力發電無法成為主要之能源，主要的缺點之一為風的不穩定性；在整體電網尺度來說，風的不穩定性使風力發電不能成為基載電力，而以個別風機來看，則使風力發電機組輸出之電力呈現不穩定的狀態且使得電力轉換系統較為複雜，這情況對於小型風力發電機之系統，其擾動更較為明顯。本研究著重在垂直軸風力發電機的相關效應。垂直軸風力發電機，主要是應用於低風速時啟動之風力發電機，其構造簡單、易維修、氣動噪音小且在無方向性顧慮，在低電力需求應用上具有發展的潛力及優勢。風力發電機之轉子/葉片系統，在基本設計及製造上首要之考量為重量，重量輕之轉子/葉片系統易於在低風速時啟動；然而重量輕之轉子/葉片系統，對於風速強弱的變化較為敏感，這會讓風力發電機組所輸出之功率變的不穩定；本研究發現，若採用較重的轉子/葉片系統，將使風力發電機組之轉動慣量增加，對於風力發電機組輸出功率之穩定性是有幫助的；轉子/葉片系統轉動速度之平穩性，較不易使結構承受大的變動負荷，相對的也較不會使結構發生疲勞破壞，並且不會產生電流突波，也可以使輸出之功率較為平穩，對於電網的衝擊也會有相當程度的改善。本研究將垂直風力發電機的轉子系統，視為傳統機械上之飛輪，用飛輪之轉動動能作為一儲能及緩衝之裝置，利用有限元素分析軟體，模擬在不同風速與葉片重量的情況下，系統可得到的累積功率值，進一步可以提供未來垂直軸風力發電機轉子系統最佳化設計之參考依據。

關鍵字

系統穩定；小型風力發電機；風力發電；飛輪；垂直軸風力發電機

並列摘要

Wind energy is a clean,environmentally friendly renewable energy,However, there are still many shortcomings so that wind power there are still many shortcomings so that wind power could not become the main source of energy. One of the major shortcomings of the wind instability. In addition, the instability of wind power also makes the inverter system more complex. For the small wind turbine system, the disturbance is more obvious. This study focuses on the effect of the vertical axis wind turbine. Vertical axis wind turbine can start to generate power at the low wind speed. Its simple structure, easy maintenance, low aerodynamic noise and the concerns of the non-directional, with the development of the potential and advantages of low electricity demand applications. The primary considerations in the design and manufacturing the Wind turbine rotor and blade system is weight. The lighter weight of the rotor and blade system is usually easy to start in the low wind speed. However, the light weight of the rotor/blade system is more sensitiveto the change of wind speed, that makes the wind turbine output power becomes unstable. This study concludes that the the heavier rotor and blade system, could increase the moment of inertia of the wind turbine, which is helpful for the stability of the wind turbine output power. In this study, the rotor system of vertical axis wind turbine is fnction as traditional mechanical flywheel, the rotational kinetic energy of the flywheel as an energy storage and buffering device. The CFD software are used to simulate in different wind speed and blade weight. The system can cumulates more power with a little bit heavier rotor system, and therefore, provide a reference for future optimal vertical axis wind turbine rotor system design.